FB FMI 2016

#include <fstream>
using namespace std;
ifstream cin("fb_fmi.in");
ofstream cout("fb_fmi.out");
int mat[1001][1001], visited[1001], comp[1001];
int n, m , k, nrComp, compSol = -1, maxiComp, cnt;
void DFS(int node)
{
    for(int i = 1;i<=n;i++)
        if(mat[node][i])
        {
            mat[node][i] = 0;
            mat[i][node] = 0;
            mat[node][0]--;
            mat[i][0]--;
            if(mat[i][0] < k)
                DFS(i);
        }
}
int main()
{
    cin >> n >> m >> k;
    for(int i = 1;i<=m;i++)
    {
        int a, b;
        cin >> a >> b;
        if(mat[a][b] == 0)
        {
            mat[a][b] = mat[b][a] = 1;
            mat[a][0]++;
            mat[b][0]++;
        }
    }
    for(int i = 1;i<=n;i++)
        if(mat[i][0] < k)
            DFS(i);
    int cnt = 0;
    for(int i = 1;i<=n;i++)
        if(mat[i][0] >= k)
            cnt++;
    cout << cnt << '\n';
    for(int i = 1;i<=n;i++)
        if(mat[i][0] >= k)
            cout << i << ' ';
    return 0;
}